Perforin, COVID‐19 and a possible pathogenic auto‐inflammatory feedback loop. (22nd September 2021)

• Record Type: Journal Article
• Authors: Cunningham, Louise; Kimber, Ian; Basketter, David; Simmonds, Peter; McSweeney, Sheila; Tziotzios, Christos; McFadden, John P.
• Is Part Of: Scandinavian journal of immunology. Volume 94:Number 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-09-22
• Subjects: auto‐inflammatory -- COVID -- cytokine storm -- haemophagocytic lymphohistiocytosis -- interleukin‐6 -- natural killer cell -- perforin; Immunology -- Periodicals; 571.96
• DOI: 10.1111/sji.13102
• Languages: English
• ISSNs: 0300-9475

Abstract

Abstract: During COVID‐19 infection, reduced function of natural killer (NK) cells can lead to both compromised viral clearance and dysregulation of the immune response. Such dysregulation leads to overproduction of cytokines, a raised neutrophil/lymphocyte ratio and monocytosis. This in turn increases IL‐6 expression, which promotes scar and thrombus formation. Excess IL‐6 also leads to a further reduction in NK function through downregulation of perforin expression, therefore forming a pathogenic auto‐inflammatory feedback loop. The perforin/granzyme system of cytotoxicity is the main mechanism through which NK cells and cytotoxic T lymphocytes eliminate virally infected host cells, as well as being central to their role in regulating immune responses to microbial infection. Here, we present epidemiological evidence suggesting an association between perforin expression and resistance to COVID‐19. In addition, we outline the manner in which a pathogenic auto‐inflammatory feedback loop could operate and the relationship of this loop to genes associated with severe COVID‐19. Such an auto‐inflammatory loop may be amenable to synergistic multimodal therapy.